Investigating the hydrolysis of complex carbohydrates with salivary α-amylase

Currently, little is known about how complex carbohydrates (maltodextrins) with varying degrees of polymerisation (DP) and molecular branching interact with α-amylase in human saliva and the associated amounts and structures of generated reducing sugars. Therefore, this study aimed to investigate salivary α-amylase and the subsequent reducing sugars generated with complex carbohydrate stimuli. A secondary aim was to investigate reducing sugar generation and complex carbohydrate taste sensitivity. Whole, stimulated saliva was collected from 32 participants. Two maltodextrin samples were used (short chain maltodextrin (SCM), average DP 6, and long chain maltodextrin (LCM), average DP 20) with and without the α-amylase inhibitor, acarbose. The concentration of reducing sugars generated by the salivary α-amylase was determined and high performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) was used to investigate their molecular chain profiles. Complex carbohydrate taste sensitivity was measured using detection threshold (DT) and suprathreshold intensity perception methods (ST). The addition of acarbose significantly reduced the amount of reducing sugars generated for both LCM and SCM samples (p = 0.0001). The LCM sample produced a significantly higher amount of reducing sugars than the SCM sample (p = 0.0001). For the LCM sample, there was no effect of complex carbohydrate taste sensitivity on reducing sugar generation (all p > 0.05). For the SCM sample, evidence suggests that reducing sugar generation may be impact complex carbohydrate sensitivity (DT: p = 0.059, ST: p = 0.076). In conclusion, DP of the maltodextrins impacted the amount of reducing sugars generated. Furthermore, there was evidence to suggest that an interaction exists between complex carbohydrate taste sensitivity and the generation of reducing sugars.